So, I basically want to make my mob hold a weapon. I have all the code in place, except in the render to hold the item it seems to need to extend RenderBiped, but the model isn't a biped. What would be a smart approach of going about this?

This may not be the smartest way, but I would write my own code for rendering the item in your model's hand. Look at how vanilla Minecraft renders the item, and then apply that t your code with some translations if needed.

This may not be the smartest way, but I would write my own code for rendering the item in your model's hand. Look at how vanilla Minecraft renders the item, and then apply that t your code with some translations if needed.

I've already done some custom item rendering for some special weapons which uses the IItemRender and whatnot, is this the idea you are suggesting?